- A stop codon is a trinucleotide sequence within a messenger RNA (mRNA) molecule that signals a halt to protein synthesis. The genetic code describes the relationship between the sequence of DNA bases (A, C, G, and T) in a gene and the corresponding protein sequence that it encodes. The cell reads the sequence of the gene in groups of three bases. Of the 64 possible combinations of three bases, 61 specify an amino acid, while the remaining three combinations are stop codons.
Definition from: Talking Glossary of Genetic Terms from the National Human Genome Research Institute
- A genetic codon in messenger RNA that signals the termination of protein synthesis during translation.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
Related discussion in the Handbook
See also Understanding Medical Terminology.